Landscaping mulch is usually made from wood chips, wood bark, sawdust or other wood and plant fibers. Mulch and pine needles are widely used in landscaping because each provides a soil covering, reduces erosion, keeps soil moist and in place, reduces the growth of weeds and undesirable vegetation, and tends to retain heat in the soil. In addition to these benefits which are derived from mulch, it is also used for its decorative effects by providing beds in which shrubbery, trees, and flowers can be aesthetically set apart from the grassy areas. Thus, not only because of its functional properties, mulch and pine needles are desirable from their ability to enhance the appearance of lawns, parks, and other areas.
Unfortunately, mulch made from wood chips and fibers will tend to weather and lose its original, rich and usually brown color when exposed to sunlight and rain. This deterioration in color can become noticeable after only a few months or less. Initially, by raking or turning the mulch the unexposed mulch below the surface can be brought to the surface to begin the aging cycle again but, this is a time consuming and labor intensive process and in a few months all of the mulch has been exposed so that a gray appearance results which is much less desirable from an aesthetic point of view. Accordingly, it is one object of the present invention to provide a method whereby re-raking or re-turning the mulch is not necessary.
When pine needles are used in landscaping and for beds they, too will fade, mat down, and tend to fade. In addition, debris such as leaves and twigs that fall onto pine needles has a tendency to mingle with the needles and cling to them thus lessening their aesthetic appeal. Accordingly, it is another object of the present invention to provide a method for retarding the deterioration of pine needles and to reduce the tendency of the needles to cling to debris.
One obvious solution to the aging and fading of mulch exposed to sunlight and water is to constantly replenish the mulch. However, this is a time consuming and expensive process which is merely a temporary solution. Accordingly, it is another object of the present invention to provide a dressing for wood fiber mulch which eliminates the need for constant replacement and re-spreading of the mulch.
In the past, a wide variety of dyes, paints, stains, and pigments have been employed to impart a pleasing color but many pigments and stains raise environmental concerns and the washout of dyes can pose a problem. In addition, dyes and pigments do have a tendency to "run" and can discolor adjacent walks or patios. The use of one such dye or coloring composition is disclosed in U.S. Pat. No. 4,932,156 which was granted on Jun. 12, 1990 to Roger Underwood. However, it is an object of the present invention to avoid the use of artificial or synthetic colorants and dyes in landscaping mulch and make use of natural or environmentally compatible coloring materials.
In one method of coloring wood mulch and avoiding dyes and pigments a mass of large fiber hardwood pulp is subjected to recycling of water through the wood fibers until they have reached a desired dark uniform color. This method is described in U.S. Pat. No. 4,788,790 which was granted on Dec. 6, 1988 to Charles Zeager. However, the recycling of water through chips or fibers until they darken appear to be a rather expensive and drawn out process. Accordingly, it is another object of the present invention to provide a method of making a dark uniformly colored mulch which avoids such extensive treatment of the mulch.
In another method for coloring wood chips which is described in U.S. Pat. No. 5,192,587 the wood chips are dyed in an aqueous solution of iron oxide and carbon black which appear to be natural or environmentally compatible materials but require the use of a solution in which to dye the wood chips. Again, it is an object of the present invention to avoid the use of a process of dying wood chips.
In still another approach, a blend of biodegradable thermoplastic polymers in naturally occurring biodegradable products is described in U.S. Pat. No. 3,932,319 which was granted on Jan. 13, 1976 to Robert Clendinning et al. This method requires the obtaining and blending of an additional material which would raise the cost of the mulch product. Thus, another object of the present invention is to avoid blending or additional handling of a mulch product.
In U.S. Pat. No. 5,105,577 to Hedges the incorporation of insecticides and odorants is described as a coating on the wood chips. However, insecticides and odorants incorporated as a coating will likely deteriorate with time and lose their effectiveness. Accordingly, it is yet another object of the present invention to provide a landscape dressing method which reduces the rate of loss of effectiveness of insecticides and fragrance enhancing additives.
In U.S. Pat. No. 5,879,695 which issued on Mar. 9, 1999 to Bastiaanae et al a ground covering material is described which is a weed inhibiting covering material comprising starches as a binder, a finely divided vegetable filler, and palm oil. The finely divided vegetable matter is preferably chaff and the starch is a potato starch mixed with palm oil. This mixture is more in the nature of a coating or paste to be applied in about 4 millimeters thickness. However, this covering material is particularly for agricultural soil and appearance is not an object nor is the use of a wood mulch and the enhancement of its appearance. Accordingly, it is another object of the present invention to incorporate vegetable oils as an applied spray to enhance the appearance of wood fiber based mulch.
The foregoing and objects are achieved by my invention which is described below in the Summary of the Invention and in the Detailed Description which follows.